Material handling apparatus



Oct- 'Z,-1941- E. ca. ROBlNSO N 2,258,125

I MATERIAL HANDLING APPARATUS Filed March 21, 1940 2 Sheets-Sheet 1INVENTOR.

ATTORNEYJ Oct. 7, 1941-. E. G. ROBINSON MATERIAL HANDLING APPARATUS 2Sheets-Sheet 2 INVENTOR.

I 7 Filed March 21, 1940 ,QM. AAA. @TTQRNEYS Patented Oct. 7, 1941UNITED STATES PATENT OFFICE 2,258,125 MATERIAL nannnnm APPARATUS Eva-yaa. Robinson, New York, N. Y. Application March 21, 1940, Serial No.325,132

3 Claims. (cl. 302-53) This invention relates to material-handlingapparatus of the general type to which my patent application Serial No.277,231, filed June 3, 1939, is directed, the present apparatus, likethe apparatus disclosed in the application just mentioned, being adaptedfor use in the pneumatic handling of various materials of granular,flocculent, pulverulent or similar nature.

Although apparatus characterized according to the invention defined inthe above application have proved highly successful in the pneumaticconveying of material, it has been found desirable to continue to supplythe container with air under pressure until the material, pursuant tocomplete removal of such material from the container, is in its entiretydispelled from the discharge conduit line. The length of time requiredfor complete evacuation of the discharge conduit line, pursuant tocomplete romoval of the material from the container, is dependent, atleast in Fig. 2 is an enlarged, fragmental, sectional Figll;

FlFig. 4 is a sectional view taken on line 4-4 of Fig. 5 is a central,longitudinaLsectional view. of the nozzle assembly of the injector unit,

Fig. 6 is an end view showing the nozzle assembly as it appears from theright in Fig, 5,

' and part, upon the length of that line. In instances where anextremely long discharge conduit line is employed, the time required toeflect complete removal of the material therefrom, after the receptaclehas been evacuated, may be of a duration comparable with; the timerequired to recharge and evacuate the container. This means that where,for example, three minutes are required to charge the container withmaterial, and like periods are required to evacuate the container and toefiect complete removal of the material from the discharge conduit line,there is a time loss of three minutes encountered during each cycle ofoperation.

An important object of the present invention is to obviate time lossesof the above character,

thereby-in effect-speeding up the cycle ofoperation and thus increasingthe efliciency of the apparatus.

To the above and other ends I contemplate improved injector meansdisposed in the discharge conduit line and constructed to so function asto effect complete removal of material from that line following eachevacuation of the container, thus making it practicable to open thecontainer and re-charge it without waiting for the discharge conduitline to relieve itself of its material content.

Other objects and advantages of the invention will become apparent fromthe following description when taken in connection with the accompanyingdrawings, in which- Fig. 1 is a view partly in section and partly inelevation of an apparatus embodying the present invention;

Fig. 7 is an enlarged, fragmental, sectional view of the distributorelement shown in Figs. 21 and 6, the section being taken on line ll ofAlthough the present invention is adapted for use in connection withvarious forms of receptacles or containers, it is herein illustrated inassociation with a container Ill particularly de--' signed for use inthe handling of pulverulent materials, notably cement. The container ispreferably cylindrical at its upper end and is there provided with adome-like header I I having a filling opening, not shown, with which isassociated a closure 12 adapted to be clamped or otherwise held insealed position so as to guard against the escape of air by way of thefilling opening during the unloading operation. The lower portion of thecontainer I0 is so shaped that its wall I, which is inclined at an angleof 60 to the horizontal, presents an inverted frustum of a cone. Thecontainer l0 may be adequately supported on a suitable base which isfragmentally shown at l5 and from which extend upwardly a plurality ofpost-like frame members l6 suitably connected to the inclined wall ll ofform, respectively, with the horizontal an angle of it follows thatthese walls are disposed at an angle 01' 60 to each other and form witheach other at the lower end of the container an 'the bottom-forming unit|1. As to the cowl 22,

it will be observed that its wall 24, which is inclined at an angle of60 to the horizontal presents an inverted frustum of a cone, the wall 24being disposed in a parallel relation to, and spaced from, the inclinedwall I8 of the bottom-forming .unit H. The wall 24 of the cowl 22 ismaintained in a definite spaced relation to the wall ll of thebottom-forming unit H by a plurality of spacing lugs 25 interposedbetween the two'walls and suitably secured thereto.

From the foregoing it will be understood that the cowl 22 and thebottom-forming unit II are so cooperatively related that they constitutea pick-up nozzle, indicated generally by the reference character N, suchnozzle being characterized by the fact that the wall 24 of the cowl 22forms with the wall l8 of the bottom-forming unit |1 an annular ejectorpassage which communicates at it slower end directly with the containerIn. The upper end of the cowl 22 is suitably connected to and is adaptedto communicate with a discharge conduit 26, leading from the container lby way of its side wall and constituting a portion of a dischargeconduit line L which is of such length as is required to convey thematerial to a desired point of delivery.

Some materials, such as dry or powdered cement, have a tendency to packinto a highly compact mass when introduced into the container I0; andwith this in mind, means are herein provided for loosening such materialby aeration, so that the pick-up nozzle N may operate to eflicientlyefiect removal of the material from the container. The aerating meansherein illustrated is in the form of a fluid pressure distributor unit Dwhich includes an annular metal ring 21, provided with a multiplicity ofapertures 28, the ring being welded throughout its outer and innermargins to, and thus forming a gastight union with, the inclined wall l4of the container l0 and the inclined wall l8 of the bottom-forming unitl1. Disposed upon each of the margins of themetal ring 21 is an elasticannular gasket 30, the gaskets being of a suitable material such as theproduct known commercially as neoprene. The gaskets 30 are spaced fromeach other and carry thereon, in a normally spaced relation to the metalring 21, an elastic annular or' ring-like distributor element 3|constructed of neoprene." The distributor element is provided with amultiplicity of slits 32, each of which tapers in length, as shown inFig. 2-A, from a relatively small dimension at the upper face or thedistributor element to a somewhat greater dimension at the lower face ofthat element. As to the slits 32, it may be well to mention that each ofthem is of a straightline character and that they, generally speaking,extend lengthwise of the annular distributor element 3|. That is to say,the slits 32 are disposed at right angles to such radii of thedistributor element 3| as intercept them intermediate their ends. Thegaskets 30 and the annular distributor element 3| are anchored in theirrespective positions by a plurality of bolts 34 which pass through apair of compression rings 35 disposed on the distributor element 3| atits inner and outer margins. In order that air under pressure may bedelivered to the lower portion of the V-shaped material-receivingchannel 2|, which in the present embodiment of the invention serves asan annular conduit peculiar to the distributor unit D, the container |0is provided with a pair of pipe fittings 36 and 25 to which areconnected branch pipes 31 and 31' of an airpressure supply pipe 38equipped with a valve 40 and adapted to be connected to an aircompressor, not shown, or other source of air pressure supply.

Interposed in the discharge conduit line L and forming a part of suchline is an injector unit 4|, which includes a pair of pipe fittings suchas standard reducers 42 and 44. These fittings when connected togetherat their larger ends through the medium of their flanges 42' and 44constitute an injector housing which tapers toward its opposite ends,the outlet end of the housing being connected through the medium of itsflange to the adjacent section of the discharge conduit line L and theinlet end of the housing being connected through the medium of itsflange to a ring-like fitting 45. The fitting 45 is provided with aninwardly extending boss 45 which, together with the annular portion ofthe fitting, is so. cored or drilled as to afford a radially extendingair duct 41 which terminates in the vicinity of the center line of thefitting and there extends axially in a direction generally away from thecontainer Ill. Associated with the ring-like fitting 45 is a distributornozzle 48, the

inlet end of which registers with the air duct 41, into which compressedair may be delivered from a suitable source, not shown, by way of asupply pipe 50 connected to the ring-like fitting and communicating withthe air duct thereof, the delivery of air to the distributor nozzlebeing under the control of a valve 5| disposed in the supply pipe 5|].It may be well to mention that, for the sake of convenience, thering-like fitting 45 and distributor nozzle 48 are separately formed andare then united by welding them together, as at 52. Although thedistributor nozzle 45 is disposed in the general line of fiow ofmaterial through the discharge conduit line L, such material passessubstantially unobstructedly over the nozzle due to the ample clearancethat is afforded around the same and due to the gradual slope of theouter wall surface of the nozzle. By so forming the nozzle 48 and itssurrounding fitting 44 as to permit unobstructed flow of the materialover such nozzle, excessive abrasive action by the material on theseparts of the injector unit is obviated. In orderto resist abrasiveaction by the moving material on the forward face of the boss 46, suchface is curved to present a substantially semi-cylindrical surface andis provided with a coating 54 of abrasion-resisting material, such asStellite."

In order that the compressed air entering the nozzle 48 may be deliveredto and commingled with the material as it passes through the injectorunit 4|, such nozzle is provided at its outlet end with an elasticdisc-like distributor element 55 which is constructed of neoprene andprovided with a plurality of slits 56, each of which tapers in lengthfrom a relatively small dimension at the outer face of the distributorelement to a somewhat greater dimension at the inner face of thatelement. It may be well to mention that each of these slits 56 is of astraight-line character and that they, generally speaking, aredisposed-in circular groups about the center of the distributor element55, which is secured at its peripheral margin to the nozzle 48 by aplurality of lag screws 51 which pass through a clamp ring 58,disposedin a face relation to and engaging the peripheral margin of thedistributor element.

In order that communication between the discharge conduit 25 and theinjector unit 4| may be severed under certain operating conditions, acut-off valve 60 is provided. This valveis 0021-, nected, through themedium of one of its flanges, to the forward or inlet end of thering-like fltting 45 and is connected, through the medium of its otherflange, to the discharge conduit 26 so that the valve, like thedischarge conduit 28 and the injector unit 4|, constitutes a portion ofthe discharge conduit line L by way of which material is conveyed fromthe container ill to any remotely located point of discharge that may bedesired. I

o The operation of the apparatus is as follows:

After conditioning the apparatus for use by introducing into thecontainer Hi the material to be conveyed, the closure I2 is anchored insealing position, whereupon compressed air is introduced into thecontainer by way of the supply pipe 38 and its associated branch pipes31 and 31' until a suitable operating pressure is built up within theapparatus. During such time as the compressed air is being introducedinto the container l0, it passes into the distributor unit D from whichit escapes by way of the multiplicity of slits 32. As the compressed airescapes from the distributor unit-D it passes up throu h the materialcarried within the container Ill and in so doing the material, such ascement in dry or powdered form, is effectively loosened or aerated.After aerating the material, thus conditioning it for removal, and whilecontinuing to introduce compressed air into the container III, the valve80 is opened with the result that the material is caused to enter thepick-up nozzle N under the influence of a flowing stream of air enteringthat nozzle from the container, the material being carried from thepick-up nozzle and out of the container through the discharge conduitline L to any remotely located point of discharge that may be desired.Due to the fact that the distributor unit D is provided with amultiplicity of slits 32 and is located slightly below, and in closeproximity to, the inlet of the pick-up nozzle N, I am enabled to cffectsuch aeration of the material in the immediate vicinity of the inlet ofthe pick-up nozzle that the material, even prior to the instant itenters the pick-up nozzle, is placed in a state of air suspension, thuspromoting eiilcient and reliable functioning of the device as amaterialhandling apparatus. As the material is removed from the lowervicinity of the mass, downward movement of the remaining material underthe action of gravity is insured due to the relatively steep inclinationof the wall l4 of the container in and the wall 24 of the cowl 22. whichwalls serve to guide the material in its downward travel into theimmediate vicinity of the inlet of the pick-up nozzle N, where itundergoes aeration preparatory to its being pneumatically delivered fromthe container by way of the discharge conduit 26. Inasmuch as the entirebulk of material moves into the relatively narrow V-shapedmaterial-receiving channel 2| where it is subjected to aeration in thevicinity of the inlet of the pick-up nozzle N, it follows that completeremoval of the material may be effected by the apparatus embodying thepresent invention.

Incident to the completion of the removal of the material from thecontainer Ill, the valve 5| is opened and the valve ll is closed,whereupon the valve 40 is closed preparatory to re-charging thecontainer III with material. During such time as the container in isbeing re-charged with material, movement of the column-like load ofmaterial, traveling in a state of air-suspension within the dischargeconduit line L intermediate the outlet end thereof and the injector unit4|, is maintained under the action of the compressed air admitted to thedischarge conduit line by way of the injector unit. It is to be observedin connection with the injector unit 4| that since.

this unit is brought into operation while the column-like load ofmaterial is moving under the influence of compressed air entering thedischarge conduit line by way of the pick-up nozzle N the valve 60 maybe closed, preparatory to conditioning the container III forre-charging, without impeding the movement of the columnlike loadthrough the discharge conduit line. The movement of the column-like loadof material through the discharge conduit line L pursuant to closing thevalve 60 may be regarded as a scavenging operation which is continuedunder the action of the injector unit 4| until such time as thedischarge conduit line is completely evacuated of its material load.

By carrying out the scavenging operation in the manner above described,certain advantages count that were movement of the material iri thedischarge conduit line discontinued such material would precipitate outof its state of air suspension and collect in such quantities in thedischarge conduit line, especially at the low or valley points therein,that it would so obstruct that line as to cause complete clogging of thesame.

Although in the foregoing description of operation of the apparatus, theinjector unit 4] is described as being utilized only after completeremoval of the material from the container has been eifected, it may bewell to here point out that the injector unit may be employed duringsuch time as the container is being evacuated, in which case the actionof the air entering the discharge conduit 25 as a material-translatingmedium, is augmented by air which is delivered.

by way of the injector nozzle 48 to the flowing stream of material inthe vicinity of the distributor element 55 where additional aeration ofthe material is effected under the action of the plurality of airstreams issuing from the several slits 58 of that distributor element.In cases where it is found desirable to utilize the injector unit 4| atthe same time the air content of the container I0 is being employed toevacuate that container, scavenging of the discharge conduit line L iseffected by the injector unit in the manner already described byallowing the valve 5| to remain open a sufllcient length of time,subsequent to the closingof the valve 60, to insure complete evacuationfrom the discharge conduit line.

Referring again to the slits 32 of the distributor element 3 I it hasbeen found that their side walls impinge against each other with ampleintimacy to prevent even such material as dry or powdered cement fromfiltering into the slits either during such time as the container "isbeing charged or during such time as the material is allowed to remainstored therein. The impingement of the side walls of the slits 32against each other is accounted for by the fact that the slits normallytend to close themselves due to the inherent elasticity of the materialfrom which the distributor element 3| is made and is further accountedfor by the distortion to which the distributor element is subjectedunder the weight of material within the container l0. Undue distortionof the distributor element 3| under the weight of the material withinthe container is obviated, however, because of the presence of the metalring 21, into engagement with which the distributor element throughout aportion of its lower surface is bulged when distorted to a substantialextent. Upon introducing air pressure into the distributor unit D,aeration of the material is initiated,whereupon the material issufficiently aerated to immediately relieve the distributor element 3|of the weight of the material and thus permit the force of thecompressed air against the distributor element to bulge that elementupwardly. Such upward bulging or distortion of the distributor element3i appears, in practice, to provide for a freer passage of air throughthe slits 32 than is possible during the initial stage of the aeratingprocess, which stage is represented by that period of time required forsuch aeration to be effected as will permit the distributor element tobe distorted from its downwardly bulged condition to its upwardly bulgedcondition. It is believed that the freer flow of air through the slits32 incident to upward bulging of the distributor element 3| is due, atleast in part, to the fact that the slits respectively taper in length,as shown in Fig. 2--A, from a relatively small dimension at the upperface of the distributor element to a somewhat greater dimension at thelower face of that element, it being noted in this connection that thelonger slitlength so compensates or ofisets any restriction of the lowerend of the slit that may be effected incident to upward bulging of thedistributor element that the slit, after having been enlarged at itsupper end incident to the upward bulging of the distributor element,represents, or is comparable with, an aperture having a uniform-orsubstantially uniform cross- -sectional dimension from its point ofinlet to its point of outlet.

Although the slits 32 have been described with particularity concerningtheir closed condition when the distributor element 3| is bulgeddownwardly andtheir opened condition when that element is bulgedupwardly, it is to be particularly noted that the walls of these slitsengage each other with sufficient intimacy at all times, err--v ceptwhen the aerating step is being carried out, to prevent even suchmaterials as dry or powdered cement from filtering into the slits. Thismeans, of course, that even though the quantity of material within thecontainer may be insufficient in weight to cause downward deflection ofthe distributor element, filtering of such material into the slits iseffectively obviated. Needless to say that during the carrying out ofthe aerating step, material is prevented from entering the slits 32because of the existence there of the film-like streams of air passingthrough these slits.

Referring to the slits 55 of the distributor element 55, it may be wellto point out that their walls, like the walls of the slits 32 with whichthe distributor element II is provided, engage each other withsufllcient intimacy at all timesexcept when air is being introduced intothe discharge conduit line L by way of the distributor nozzle 48-toprevent even such materials as dry or powdered cement from filteringinto the slits. Needless to say that during such time as air is beingintroduced into the discharge conduit line L by way of the distributornozzle 48, material is prevented from entering the slits 55 because ofthe existence then of the film-like streams of air passing throughtheslits. It is to be observed that during such time as air is beingintroduced into the discharge conduit line L by way of the distributornozzle 48, the distributor element 55 is distorted or bulged outwardlyso that its outer face presents a convex surface. Such bulging of thedistributor element 55 afiords a free flow of air through the slits 56;and it is believed that such free flow is due, at least in part, to thefact that the slits respectively taper in length, as shown in Fig. 5,from a relatively small dimension at the outer face of the distributorelement to a somewhat greater dimension-at the inner face of thatelement, it being noted in this connection that the longer slit lengthso compensates or offsets any restriction of the inner end. of the slitthat may be eflected incident to outward bulging of the distributorelement that the slit, after having been enlarged at its outer endincident to outward bulging of the distributor element, represents, oris comparable with, an aperture having a uniform or substantiallyuniform crosssectional dimension from its point of inlet to its point ofoutlet. Although the distributor element 55 is not likely to besubjected to any influence which would effect inward bulging thereof, itgoes without saying that should there be encountered any condition whichwould effect inward bulging of the distributor element, such bulgingwould cause the side walls of the slits 56 to more intimately engageeach other (as described in connection with the slits 32 of thedistributor element 3| incident to downward bulging thereof) and thusfurther insure against entrance of material into the slits.

It should be observed that should any material, such as powdered cementin the presence of moisture, assume the'form of a hard or solidifiedmass overlying, and thus tending to obstruct, any one of the slits 32 ofthe distributor element 3! or any one of the slits 55 of the distributorelement 55, such mass of obstructing material is readily disrupted, onthe one hand, under the action of air pressure within the distributorunit N and,-on the other hand, under the action of air pressure withinthe distributor nozzle 48, as will be readily understood when it istaken into account that these distributor elements, incident to theintroduction of air into the distributor unit N and distributor nozzle48, become sufiiciently bulged upwardly and outwardly, respectively, toso dislodge the obstructing mass as to insure unimpeded delivery of airby 'way of the slits 32 and 56.

Although only one form of the invention is herein illustrated anddescribed, it is to be understood that various changes may be resortedto without departing from the spirit of the invention or the scope ofthe following claims.

ciated with said nozzle and comprising a mass What is claimed is:

1. A material-handling apparatus comprising a container adapted for thereception of material to be removed therefrom, a discharge conduit lineleading from said container, and an airdelivery unit by way of whichcompressed air is delivered to said container to facilitate removal ofmaterial therefrom, said air-delivery unit comprising a mass ofdistensible elastic material having slit-like openings therein by way ofwhich compressed air is directed into said container from saidair-delivery unit, said openings being normally closed to passage ofmaterial thereinto from said container and having at their respectivedischarge ends a slit-length substantially less than the slit-length attheir respective inlet ends.

2. A material-handling apparatus comprising a container adapted for thereception of material to be removed therefrom, a discharge conduit lineleading from said container and by way of which material upon removalfrom said container is delivered to a discharge point, and means forfacilitating passage of material to said discharge point by way of saiddischarge conduit line and including an injector unit disposed in saiddischarge conduit line, said injector unit comprising a distributornozzleinto which compressed air is directed and past which materialflows in surrounding relation thereto during its delivery from saidcontainer toward said discharge point, and a distributor element assoofdistensible elastic material having slit-like openings therein by way ofwhich compressed air is directed into said discharge conduit line fromsaid nozzle, said elastic material being distensible in the generaldirection of flow of material past said nozzle incident to delivery ofcompressed air to said nozzle and said openings being normally closedand having at their respective discharge ends a slit-lengthsubstantially less than the slit-length at their respective inlet endsand being distensible incident to delivery of compressed air to saidnozzle so as to afiord paths of communication between said nozzle andsaid discharge conduit line.

3. For use in a material-handling apparatus of the type including acontainer in association with a discharge conduit line by way of whichmaterial upon removal from the container is delivered to a dischargepoint, material-aerating means comprising a distributor element in theform of a mass of distensible elastic material ha ving slit-likeopenings therein by way of which compressed air is delivered foraerating purposes, said openings being normally closed and having attheir respective discharge ends a slit-length substantially less thanthe slit-length at their respective inlet ends and being distensibleincident to the passage of compressed air therethrough.

EVELYN G. ROBINSON.

